21021211112212 has 6 divisors (see below), whose sum is σ = 36787119446378. Its totient is φ = 10510605556104.

The previous prime is 21021211112207. The next prime is 21021211112219. The reversal of 21021211112212 is 21221111212012.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 20738150935056 + 283060177156 = 4553916^2 + 532034^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 21021211112212.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21021211112219) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2627651389023 + ... + 2627651389030.

Almost surely, 2^{21021211112212} is an apocalyptic number.

It is an amenable number.

21021211112212 is a deficient number, since it is larger than the sum of its proper divisors (15765908334166).

21021211112212 is a wasteful number, since it uses less digits than its factorization.

21021211112212 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5255302778057 (or 5255302778055 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 19.

Adding to 21021211112212 its reverse (21221111212012), we get a palindrome (42242322324224).

The spelling of 21021211112212 in words is "twenty-one trillion, twenty-one billion, two hundred eleven million, one hundred twelve thousand, two hundred twelve".